DE102014118215B3 - Device with a measuring head - Google Patents

Abstract

The invention relates to a device with a measuring head with an exchangeable receptacle for at least one sensor and / or at least one rotary / pivot joint and / or at least one pushbutton, wherein the measuring head has a device for generating a first holding force, wherein the measuring head has a second Having a device for generating an additional holding force.

Description

The invention relates to a device with a measuring head.

The prior art includes various devices with a measuring head, for example, coordinate measuring machines with a switching or measuring probe or machine tools with corresponding measuring heads. From practice, various arrangements are known to arrange a probe or sensor on a measuring head. The coordinate measuring machines known from practice and the probes used there have a mechanical interface which allows different probe configurations to be automatically interchanged.

Such a measuring head is from the DE 100 30 570 A1 known. The known from this prior art interface consists of three storage units on the probe and a so-called button recording with the corresponding counterparts to the storage units. The required buttons are screwed into the button holder. The bearing components on the receptacle, consisting for example of three balls, sit in the corresponding bearing parts on the probe. A holding device in the probe pulls the receptacle, which has a latching possibility for the holding device, with a defined force in the three camps. The holding device may consist of a spring and / or a magnet.

This type of storage allows a very precise and highly accurate reproducible seat of the recording on the probe. This is absolutely necessary in order to be able to form relationships between them during measurements with different buttons.

From the cited prior art, it is known to pull the button recording by a hook in the three storage units. The force for this creates a spring in a cylinder. If the hook is to be opened in order to release the mechanical connection, compressed air is applied to a piston to which the hook is fastened, thereby bridging the spring.

If higher holding forces are required on the hook, in practice the spring is replaced by a spring with a higher force. However, this force must never exceed the force reached at the piston with the help of compressed air, otherwise the hook can not be opened by the compressed air.

The prior art ( DE 40 25 829 A1 ) includes a holder for a probe of coordinate measuring machines. This holder consists of two clamping devices, wherein the first clamping device is designed in the manner of a suction cup and is subjected to a negative pressure to hold the button. The second clamping device is designed as a permanent magnet. This belonging to the prior art device has the disadvantage that the weight of different heavy push button is not considered.

Furthermore belongs to the state of the art JP H11-257 307 A a measuring head with a push button. The measuring head has two spaces subject to compressed air and, in addition, a spring. Also, this belonging to the prior art device has the disadvantage that the weight of different heavy button is not considered.

The technical problem underlying the invention is to provide a device with a measuring head, in which the holding force is greater than in the prior art devices to keep even high-mass or high-torque buttons safely in the camps.

This technical problem is solved by a device having the features according to claim 1.

The device according to the invention with a measuring head with an exchangeable receptacle for at least one sensor and / or at least one rotary pivot joint and / or at least one pushbutton, wherein the measuring head has a device for generating a first holding force,
wherein the measuring head has a second device for generating an additional holding force, wherein the measuring head has a double piston system and wherein the additional second device is designed as a pneumatic counter-piston, characterized in that an air supply of the pneumatic opposed piston is formed coupled with a pneumatic counterbalance ,

The device according to the invention has the advantage that an additional holding force is generated by the second device, which is added to the first holding force. As a result, the total holding force is increased in order to hold high-mass or high-torque buttons that arise, for example, asymmetrically distributed laterally mounted masses safely in the camps.

According to the invention it is provided that the measuring head has a double piston system and that the additional second device is designed as an opposing piston.

Due to the double piston system, there is the possibility that the piston on which the Receiving for the at least one sensor and / or the at least one rotary swivel joint and / or at least one push-button is attached, also from the side, for example, with air, can be applied, which is arranged in the direction of the recording. Thus, an additional force to the device that generates the first holding force can be generated and the holding force is thereby increased.

According to a further advantageous embodiment of the invention, at least one spring and / or at least one magnet is provided for generating the first holding force.

These two devices work reliably and are inexpensive.

According to the invention, the counter-piston is designed as a pneumatic counter-piston. Especially in the field of coordinate measuring machines, it has proven to be advantageous to work with air, since no soiling occurs, such as when using hydraulic systems with oil.

According to a further particularly preferred embodiment of the invention, it is provided that an air supply of the pneumatic counter-piston is formed coupled to a pneumatic counterbalance.

The pressure supply on the receiving side of the measuring head is additionally connected to a further, for example, pneumatic piston, which is arranged in a cylinder. The piston is advantageously connected to a spring. The spring is preferably attached to a stationary relative to the so-called Z-swing arranged component of the measuring head. By the operation of the piston, which acts on the spring and which is arranged on the Z-direction movable Z-swing, the Z-swing is pulled up against gravity in order to carry out a weight balance for various buttons, swivel joints or sensors can.

According to a further advantageous embodiment of the invention, it is provided that the at least one spring is designed as a spring supporting the receptacle in the event of a failure of the additional holding force.

If the additional holding force is omitted, for example, if there is a loss of air, it is necessary for the spring generating the first holding force and / or the magnet generating the first holding force to receive the receptacle for the at least one sensor and / or the at least one rotary pivot joint and / or the at least one picks up a button to prevent damage to the sensor, the swivel joint and / or the button.

A further advantageous embodiment of the invention provides that the device is designed as a coordinate measuring machine. Coordinate measuring machines are used in many areas and the buttons and / or optical sensors and / or rotary swivel joints are exchanged depending on the application. Since in practice more and more widely projecting stylus systems are used, it is particularly advantageous to use the invention in a coordinate measuring machine in order to generate the increased holding force required for high-mass and high-torque probes for reproducible measurements.

A further advantageous embodiment of the invention provides that a shaft of the receptacle is fixedly connected to the double piston, that the double piston is arranged in a space can be acted upon with air and that at least one seal for the guided into the space shaft is provided.

The receptacle is fastened to the piston, for example, by means of a shaft. For this purpose, the shaft must be guided into the space that can be acted upon with air, since the piston is arranged in this space. For this purpose, the shaft is advantageously sealed by a seal, which is arranged in the region of the passage opening of the shaft, with respect to the space which can be acted upon with air.

According to the invention, it is thus provided that the achievable total force is composed of the first holding force, for example the spring force or magnetic force, and the additional holding force, that is to say the force acting on the piston. Due to the shaft for the intake, the force that can be achieved at a certain air pressure on the underside of the piston is slightly lower than the force on the upper side at this pressure.

Further features and advantages of the invention will become apparent from the accompanying drawings, in which an embodiment of a measuring head for a coordinate measuring machine is shown only by way of example. In the drawing show:

1 a measuring head according to the prior art in longitudinal section;

2 a measuring head according to the invention in longitudinal section;

3 a plan view of an arrangement of three abutments.

1 shows a measuring head 1 , the three camp units 2a . 2 B . 2c of which in 1 only the storage units 2a . 2 B are shown.

In addition, a button recording 4 provided in which a button 5 is screwed. The button recording 4 has bearing components 3a . 3b . 3c on, of which in 1 only the bearing components 3a . 3b are shown. The bearing components 3a . 3b . 3c are formed as spheres. These are placed in the corresponding storage units 2a . 2 B . 2c at the measuring head 1 , A holding device 6 , which is designed as a hook, pulls the button receptacle 4 which is a latching device 7 for the holding device 6 having, with a defined force in the three camps 2a . 2 B . 2c ,

This type of storage allows a very precise and highly reproducible seat of the probe holder 4 at the measuring head 1 , This is absolutely necessary in order to be able to form relationships between them during measurements with different buttons.

The button recording 4 gets through the hook 6 in the storage units 2a . 2 B . 2c drawn. The power for this creates a spring 8th in a cylinder 9 , Should the hook 6 to be opened, to release the mechanical connection, becomes a piston 10 with compressed air 11 charged and the spring 8th is thereby bridged.

If larger holding forces are to be generated, springs with a larger holding force can only be used to a certain degree. In many cases, for reasons of space, the use of a spring with greater holding power in the measuring head 1 not possible.

2 shows a measuring head according to the invention 1 ,

Same parts in 1 and 2 are provided with the same reference numbers.

At the measuring head 1 is in the cylinder 9 a double piston system 13 arranged. The double piston system 13 with the piston 10 can from one of the button recording 4 opposite side through an inlet opening 11 as well as on one of the button recording 4 facing side through an inlet opening 12 be acted upon with compressed air. Is through the inlet opening 12 that is the receiving side of the piston 10 made an application with compressed air, an additional force acts on the spring 8th , whereby the total holding force is increased. The total holding force is thus made up of the spring force of the spring 8th and the force generated by the compressed air flowing through the inlet opening 12 is fed and on the piston 13 works together.

A shaft 14 of the hook 6 is through a seal 15 in the cylinder 9 sealed. Through the shaft 14 for the hook 6 is the force that can be achieved at a certain air pressure on the underside of the piston 10 slightly lower than the force on the top at this pressure.

In addition, the pressure supply on the receiving side of the piston 10 with another pneumatic piston 16 in a cylinder 17 connected. The cylinder 17 stands over an opening 18 with a room 21 of the cylinder 9 in connection. The piston 16 is with a spring 19 on the stationary part of the measuring head 1 attached, coupled. An only schematically indicated Z-swing 20 is through the system consisting of cylinders 17 , Piston 16 and spring 19 , moved in z-direction. Will the room 21 pressurized with compressed air, so is also the space in the cylinder 17 pressurized with compressed air. This will cause the piston 16 in the direction of the button recording 4 moved, causing over the coupling with the spring 19 a movement of the Z-swing 22 usually takes place in the direction of arrow A against gravity. As a result, when exposed to compressed air of the room 21 not only a higher holding force on the hook 6 achieved, but also a weight balance of the additional weight of the probe used 5 with the button recording 4 carried out.

3 shows the bearings 2a . 2 B . 2c containing the bearing components 2 B (in 3 not shown) record. The warehouse 2a is as a plan camp, the camp 2c as V-bearing and the bearing 2c designed as a triple bearing. With this configuration, an accurate and reproducible arrangement of the bearing components 3a . 3b . 3c possible. In 3 is beyond the shaft 14 shown.

LIST OF REFERENCE NUMBERS

1

probe

2a

storage unit

2 B

storage unit

2c

storage unit

3a

bearing component

3b

bearing component

3c

bearing component

4

Probe body

5

button

6

hook

7

latching

8th

feather

9

cylinder

10

piston

11

inlet port

12

inlet port

13

Double piston system

14

shaft

15

poetry

16

piston

17

cylinder

18

inlet port

19

feather

20

Z-Swing

21

Space in the cylinder 9

Claims (5)

Device with a measuring head with an exchangeable receptacle ( 4 ) for at least one sensor and / or at least one rotary / swivel joint and / or at least one pushbutton, wherein the measuring head comprises a device for generating a first holding force for receiving ( 4 ), in which the measuring head ( 1 ) a second device ( 13 ) for generating an additional holding force, wherein the measuring head ( 1 ) a double piston system ( 13 ), in which the additional second device is designed as a pneumatic counter-piston, characterized in that an air supply of the pneumatic counter-piston is formed coupled to a pneumatic counterbalance. Device with a measuring head according to claim 1, characterized in that for the generation of the first holding force at least one spring ( 8th ) and / or at least one magnet is provided. Device with a measuring head according to claim 2, characterized in that the at least one spring ( 8th ) and / or the at least one magnet as one in case of failure of the additional holding force recording ( 4 ) supporting spring ( 8th ) or magnet is formed. Device with a measuring head according to one of the preceding claims, characterized in that a shaft ( 14 ) of the recording ( 4 ) with the double piston ( 10 ) is firmly connected, that the double piston ( 10 ) in an air-powered room ( 21 ) is arranged, and that at least one seal ( 15 ) for in the room ( 21 ) guided shaft ( 14 ) is provided. Device with a measuring head according to one of the preceding claims, characterized in that the device is designed as a coordinate measuring machine.

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